Airdata calibration and accuracy determination
An Air Data System (ADS) plays a key role in stabilization, control and improving performance of modern fighter aircraft. Airdata sensors installed on aircraft generally measures pressure and flow angles in the local flow field using vanes & probes. However, aircraft requires the free stream parameters for flying. Therefore, forward lookup tables in Air Data Computer (ADC) are used to transform local parameters to free stream parameters. Accuracy of free stream parameters depends upon the accuracy of forward lookup tables in Air data computer. These tables are already calibrated using Maximum Likelihood based Estimate software. It has been found that ADS tables needs to be updated. Hence, an Extended Kalman filtering (EKF) based technique is developed to update the existing calibrated ADS tables and to ascribe the accuracy of the airdata system.
Facilities where this technique is used: Used for updating airdata tables for the Airforce, Navy and trainer versions of LCA. The updated tables are implemented onboard LCA.